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Biomedical subjects

A J Stark

Publications and source records attributed to A J Stark.

31 records · Page 2Linked to original sources
PubMed1978

Protection of cattle against Babesia major by the inoculation of irradiated piroplasms.

Two experiments were carried out on Babesia major in splenectomised calves. In the first one, the parasite was titrated and a linear relationship was observed between infective dose (10(2)--10(7) parasites) and onset of disease. In the second experiment aliquots of 1.2 X 10(10) parasites were irradiated at doses of 24, 28, 32, 36 and 40 krads and inoculated into groups of calves, while control calves received 1.2 X 10(7) or 1.2 X 10(4) parasites. Animals which received parasites irradiated at 24 or 28 krads had mild reactions and were immune to homologous challenge. Animals receiving parasites irradiated at the higher dose levels had limited ability to resist the challenge.

Animals↗
PubMed1977

Enzyme activities in tissues of clinically normal Large White pigs. Variations with age and sex.

The activities of eight enzymes (glutamate dehydrogenase, sorbital dehydrogenase, malate dehydrogenase, lactate dehydrogenase, alpha-hydroxy butyrate dehydrogenase, gamma-glutamyl transpeptidase, alkaline phosphatase and creatine kinase) were determined in tissue homogenates of liver, kidney, spleen, lung, small intestine, cardiac muscle and skeletal muscle, from 15 Large White pigs of three different ages (1.5 weeks, 18--22 weeks and 113 weeks). The results showed that variation in tissue enzyme concentration due to differences in sex is minimal. Variation due to differences in age, however, appears to be of greater importance, particularly when considering young animals. These age differences may affect the interpretation of plasma enzyme changes due to tissue damage, and the use of additional enzyme assays as an aid to interpretation in these cases is advisable.

Age Factors↗
PubMed1977

The blood composition of different breeds of bulls undergoing beef performance tests.

Blood samples taken on three occasions from each of 66 bulls undergoing beef performance tests were analysed for packed cell volume, blood glucose, haemoglobin, serum albumin, urea nitrogen, total protein, inorganic phosphate, Ca, Ca, Mg, K, Na, Cu, Fe and total iron binding capacity. The bulls were individually fed and situated at two centres, one accommodating Lincoln-Red, Devon and Sussex breeds and the other, Hereford. Significant differences between the Lincoln-Red, Devon and Sussex breeds were observed in concentrations of glucose, urea nitrogen, total iron binding capacity (P less than 0.001), Ca (P less than 0.01), Na and Cu (P less than 0.05). There were no significant correlations between the growth rates of individual bulls and their blood composition.

Animals↗
PubMed1977

Babesia divergens in splenectomised calves: titration of the infective dose.

Two experiments were carried out in which Babesia divergens was titrated in splenectomised calves. In the first experiment, a linear relationship was observed between infective dose (10(5)--10(9)) parasites) and onset of disease. In the second experiment, a similar trend was observed for infective doses of 10(2)--10(6) parasites, but 10(3) parasites appeared to be the minimum dose required to produce overt disease or resistance to homologous challenge in inoculated animals.

Animals↗
PubMed1976

The influence of dietary protein intake on milk production and blood composition of high-yielding dairy cows.

Cows were fed either 75 or 100% of the recommended intake levels for protein and 100% of recommended energy levels (Agricultural Research Council, 1965) from 8 weeks pre-calving until 14 weeks post calving. From 14 weeks post calving and to the end of lactation all the cows received 100% of the recommended protein and energy intakes. The mean of the 305-d milk yields of the 2 groups was not significantly different and although cows on the lower protein intake produced less lactose during the first 14 weeks of lactation there was no significant difference in total lactose, fat, protein or total solids production between the groups. In both groups blood packed-cell volume, red cell count and haemoglobin decreased during the first 10 weeks of lactation and then began to increase in the high-protein group. The cows receiving the low-protein diet showed a similar increase only when they received the high-protein ration from 14 weeks post calving. The mean interval from calving to conception was 27-5 weeks in the high-protein group and 20 weeks in the low-protein group. It is concluded that feeding 75% of protein requirements to dairy cows during the first 14 weeks of lactation does not reduce milk yield or quality significantly and probably has no adverse effect on fertility.

Animals↗
PubMedDate not supplied

An approach to estimating future manpower requirements in physical and occupational therapy.

This paper reports the approach used in a physical therapy (PT) and occupational therapy (OT) manpower requirements study conducted in British Columbia, Canada. A total of 426 questionnaires were mailed to likely employers of PTs and OTs, and to PTs in private practice. After telephone reminders and a second mailing, the overall response rate was 83.3%. The results of the survey indicated that, by 1986, respective PT and OT department heads were anticipating a 60% increase in demand for PTs and a 102% increase for OTs, while agency administrators were suggesting a 76% increase for PTs and a 142% increase for OTs. Although a variety of factors--all largely beyond the control of both respondents and researchers--will determine the degree to which these estimates actually reflect the future demand for these manpower groups, it should be noted that, for both disciplines, the anticipated increase was substantially greater than the level experienced in the five years preceding the survey. The estimation approach used in this study considers nonrespondents; it is a procedure which permits investigators to offer a more accurate picture of the current manpower situation while using a more realistic base on which to estimate future requirements. The development of the requirement side in the supply/requirement equations of manpower studies may be well served in the future with this approach.

British Columbia↗